ATP-binding cassette transporter protein (ABC transporter)

ATP-binding cassette transporter proteins (ABC transporters) are a large superfamily of multipass transmembrane proteins that utilize the energy from ATP hydrolysis to transport a wide variety of substrates—including ions, amino acids, peptides, lipids, metabolites, drugs, and toxins—across biological membranes. They are found in all kingdoms of life and are characterized by conserved nucleotide-binding domains (NBDs) and transmembrane domains (TMDs). In humans, at least 48 distinct ABC transporter genes exist, grouped into subfamilies (ABCA–ABCG), many of which play crucial roles in drug efflux, absorption, and resistance, regulation of physiological substrate levels, and disease processes such as cancer multidrug resistance and cystic fibrosis. ABC transporters may be importers or exporters and are implicated in essential cellular functions as well as numerous inherited and acquired human diseases. Their activity can profoundly affect the pharmacokinetics of multiple drug classes and influence patient response and safety profiles.

Other names

ABC transporterATP-binding cassette (ABC) transporterABC cassette transporterABC protein

Substrate efflux to reduce intracellular drug/toxin concentration (drug resistance) ATP hydrolysis–driven conformational change to mediate substrate transport Maintenance of concentration gradients across membranes